From 5a51fcd1f30c0f93bb54cec7201a3690032470cb Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 6 May 2015 21:46:49 +0900 Subject: [PATCH] perf probe: Skip kernel symbols which is out of .text Skip the kernel symbols which is out of .text, e.g. the functions in .inittext. Those are found in debuginfo/kallsyms, but already freed from memory. e.g. ---- # perf probe vfs_caches_init vfs_caches_init+0 is out of .text, skip it. Probe point 'vfs_caches_init' not found. Error: Failed to add events. ---- Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Ananth N Mavinakayanahalli Cc: David Ahern Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150506124649.4961.56249.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 4265f2e3bd14..37a3a8b04a69 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -557,8 +557,9 @@ static int post_process_probe_trace_events(struct probe_trace_event *tevs, bool uprobe) { struct ref_reloc_sym *reloc_sym; + u64 etext_addr; char *tmp; - int i; + int i, skipped = 0; if (uprobe) return add_exec_to_probe_trace_events(tevs, ntevs, module); @@ -572,19 +573,29 @@ static int post_process_probe_trace_events(struct probe_trace_event *tevs, pr_warning("Relocated base symbol is not found!\n"); return -EINVAL; } + /* Get the address of _etext for checking non-probable text symbol */ + etext_addr = kernel_get_symbol_address_by_name("_etext", false); for (i = 0; i < ntevs; i++) { if (tevs[i].point.address && !tevs[i].point.retprobe) { - tmp = strdup(reloc_sym->name); - if (!tmp) - return -ENOMEM; + /* If we found a wrong one, mark it by NULL symbol */ + if (etext_addr < tevs[i].point.address) { + pr_warning("%s+%lu is out of .text, skip it.\n", + tevs[i].point.symbol, tevs[i].point.offset); + tmp = NULL; + skipped++; + } else { + tmp = strdup(reloc_sym->name); + if (!tmp) + return -ENOMEM; + } free(tevs[i].point.symbol); tevs[i].point.symbol = tmp; tevs[i].point.offset = tevs[i].point.address - reloc_sym->unrelocated_addr; } } - return 0; + return skipped; } /* Try to find perf_probe_event with debuginfo */ @@ -630,11 +641,14 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, pr_debug("Found %d probe_trace_events.\n", ntevs); ret = post_process_probe_trace_events(*tevs, ntevs, target, pev->uprobes); - if (ret < 0) { + if (ret < 0 || ret == ntevs) { clear_probe_trace_events(*tevs, ntevs); zfree(tevs); } - return ret < 0 ? ret : ntevs; + if (ret != ntevs) + return ret < 0 ? ret : ntevs; + ntevs = 0; + /* Fall through */ } if (ntevs == 0) { /* No error but failed to find probe point. */ @@ -2403,6 +2417,9 @@ static int __add_probe_trace_events(struct perf_probe_event *pev, pr_info("Added new event%s\n", (ntevs > 1) ? "s:" : ":"); for (i = 0; i < ntevs; i++) { tev = &tevs[i]; + /* Skip if the symbol is out of .text (marked previously) */ + if (!tev->point.symbol) + continue; /* Ensure that the address is NOT blacklisted */ node = kprobe_blacklist__find_by_address(&blacklist, tev->point.address); -- 2.39.5